Forensic Limnology and Entomology
Microscopy Applications for Forensics

Forensic Limnology and Entomology

Identify and Reliably Document Biological Species From Forensic Investigations

As an expert in these fields your task is to unquestionably identify and reliably document biological species from forensic investigations with the help of optical magnification. These can stretch from nano- to micro- and macroscopic observations of certain unique characteristics of the form and surfaces of the specimen.

In forensic limnology your work usually focuses on diatoms. These micro algae can help to confirm or exclude drowning as diatoms can make their way to various organs when inhaling sea or fresh water. With their high phylogenetical diversity and well over 75.000 named taxa living in diverse and highly specific ecosystems the location of drowning or exposition of cloth to water can often be narrowed down quite precisely. After isolating the diatoms highly intricate patterned silica shells from tissue, light and/or electron microscopy imaging and documentation will follow. High-quality imaging data with good contrast and resolution enable reliable comparative analysis against diatom maps.

Forensic entomology in a medicolegal or medico criminal context focuses on insects that colonizes human tissue under certain conditions. Forensic entomology involves estimating the age of insects developing on human tissue; specifically, it involves estimating the time of colonization or time when eggs or larvae are deposited on the remains (called the minimum time since colonization) and the time elapsed since insect activity began (called the postmortem interval, or PMI).

Larder beetle, Dermestes ladarius on meat, this beetle can be a pest on animal products, forensic entomology

Larder beetle, Dermestes ladarius on meat, this beetle can be a pest on animal products, forensic entomology

Larder beetle, Dermestes ladarius on meat, this beetle can be a pest on animal products, forensic entomology
Adobe Stock Extended License
Adobe Stock Extended License

Larder beetle, Dermestes ladarius on meat, this beetle can be a pest on animal products, forensic entomology

Blowfly, Calliphora vicina, drinking portrait cECP 2020, forensic entomology  ©Ernie Cooper, Adobe Stock Extended License
Blowfly, Calliphora vicina, drinking portrait cECP 2020, forensic entomology  ©Ernie Cooper, Adobe Stock Extended License
Ernie Cooper, Adobe Stock Extended License
Ernie Cooper, Adobe Stock Extended License

Blowfly, Calliphora vicina, drinking portrait cECP 2020, forensic entomology

Forensic entomology in a medico criminal context is often used to:

  • Establish the geographical location of death
  • Associate the victim and suspect to each other
  • Identify the sites of trauma
  • Determine time of death
  • Provide alternative toxicology and DNA samples

While distinguishing the mature insect is often relatively simple the eggs, maggots (larvae) and pupa may look similar. Stereo microscopes allow a detailed dimensional view on such specimen. Without any need for sample preparation living specimen can be observed and findings recorded at any time of the lifecycle. Automated zoom microscopes and electron microscopes can provide an even higher level of documentation by improved resolution for even the most difficult samples.


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